Athletic shoe

ABSTRACT

A lightweight athletic shoe, especially a racing shoe, having a very flexible outer sole of wear-resistant material. The heel section of the outer sole is provided with a heel having such a height that the heel section has a considerably higher position with regard to the forward part of the foot than does an athletic shoe which does not have a heel. When the wearer of the athletic shoe places the heel on the ground, the heel procures for the wearer an acceleration component directed in the direction of movement.

The present invention relates to a lightweight athletic shoe, especiallya racing shoe, having a highly flexible outer sole of wear-resistantmaterial. The development of athletic shoes, especially racing shoes,football and soccer shoes, handball shoes, basketball shoes, etc., forsport contests, has for a long time been aimed at the achievement of asgood a fit as possible at as low a weight as possible. Since thebeginning of the development of athletic shoes, this led to the basicrequirement of leaving out, as much as possible, parts which, althoughcommon with conventional footwear, are not absolutely necessary for anathletic shoe. With athletic shoes of all types for sports contests, theheel is viewed as merely being extra weight. For this reason, athleticshoes for sports contests have for a long time been made without heels.

An exception to this rule are earlier developments of athletic shoes,especially racing shoes, which still had to be made relatively thick dueto the at that time still incomplete technology concerning theintroduction of spikes into the outer sole without the danger ofinitiating pressure difficulties. This rather sharply reduced theflexibility of the outer sole. The adapt to the relatively thick outersole, a heel piece having a thickness corresponding to that of the outersole was also provided in the heel region. The heel piece in thisconnection had the further purpose of securing the customary placebetween the front of the foot and the heel. (German Pat. Nos. 801898,816512, 879965 and German Gebrauchsmuster 17 10 714)

The recently introduced and extremely lightweight athletic shoes,especially racing shoes, having the known burled or knobby rubber solesor crepe rubber soles with a sole thickness of at the most 1.5 to 1.8mm, furnish together with the cover or upper an average total weight ofat the most 130 g per shoe. In addition to the lightweight constructionof the shaft with extremely thin upper material or extremely light fiberwebbing, attention was particularly directed towards achieveing a lowweight of the shoe welt and the outer sole. With racing shoes,especially for synthetic race courses, it was considered important totake advantage of the catapult effect inherent to modern race courses bymeans of a more or less expensive refinement of the spike-like grippingelements in the region of the forward sole, even if, to a certainextent, this led to an increased weight of the racing shoe.

It is an object of the present invention to develop an athletic shoe,especially a racing shoe, of the above described general type in such away that the possibilities, which the rebound effect caused bygravitation offers for acceleration of the athlete, are utilized to astill greater extent.

This object and other objects and advantages of the present inventionwill appear more clearly from the following specification in connectionwith the accompanying drawing, in which:

FIG. 1 is a side view of a customary lightweight racing shoe; and

FIG. 2 is a side view of a lightweight racing shoe according to thepresent invention.

The athletic shoe of the present invention is characterized primarily inthat that portion of the outer sole which is associated with the heelsection of the shoe is provided with a heel having such a height thatthe heel section has a considerably higher position with regard to theforward part of the foot than does an athletic shoe which does not havea heel. With this measure, the wearer of the athletic shoe, when placingthe heel on the ground, gains an acceleration component directed in thedirection of movement.

The invention is based on the knowledge that the athlete, even thesprinter in a short-distance race, no later than the beginning of thefatigue phase, also places the heel on the ground with every step afterrolling off of the ball of the foot. With the customary athletic shoes,the distance of the rearward rolling-off process from the balls to theheels is relatively great. This means that a greater amount of time istaken until the heel makes contact with the ground. In addition, due tothe low end position of the heel, the rebound effect achieved from thecontact with the ground is essentially a component which is onlyvertical to the running surface or track. This does not contribute atall to the acceleration of the athlete. In contrast, with an athleticshoe of the present invention, the distance of a complete rolling-offcycle of heel to ball to heel is reduced by twice the height of theheel. Due to the higher end position of the heel, the rebound effectgenerates a resulting acceleration component in the direction ofmovement. Furthermore, the heel sustains the forward position needed formaintaining the speed or acceleration, and prevents in particular thestumbling which is feared during the final spurt and is caused byfatigue, and which results in a loss of time. These surprisingadvantages are so considerable that compared to the somewhat greaterweight (with racing shoes the additional weight for the heel can be heldto less than 5 g per shoe) has absolutely no significance, as evidencedby thorough testing.

Referring now to the drawing in detail, the known racing shoe of FIG. 1comprises a covering or upper 1 which is kept as light as possible andis made of leather or a fiber webbing or mesh, preferably of a polyamidebase. The welt pieces 4 and 5 are located in the region of the forwardsole 2 and the heel 3. The knobby rubber soles or crepe rubber soles 6,which are of wear-resistant material and preferably extend from theforward sole 2 to the heel 3, have a thickness of 1.5 to 1.8 mm. FIG. 1shows the rolling-off process in nearly the end phase with regard to theballs of the shoe. The distance which the heel must travel in order toachieve contact with the ground (see the dashed lines in FIG. 1) isshown through the middle of the heel as H₁. Since the heel 3, uponreaching the ground 7, has a relatively low end position, the reboundeffect caused by contact with the ground generates essentially only onecomponent, which is approximately perpendicular to the running surfaceand is shown by the arrow P₁. In this instance, the rebound effect doesnot contribute to acceleration of the athlete.

The racing shoe of the present invention is shown in FIG. 2. Those partswhich are the same as in FIG. 1 have the same reference numerals. As canbe clearly seen from the drawing, the racing shoe of the presentinvention, in the region of the heel, has a distinct heel section 8,which is preferably inserted as a separate piece between the welt 5 andthe outer sole 6, and is preferably glued to these parts. When makingthe athletic shoe as a racing shoe, the heel preferably comprises aflexible elastic yet relatively slightly volume compressible material.Solid rubber is particularly suitable for this purpose. However, otherlight rubbers or porous materials may be used. When making the athleticshoe of the present invention as a racing shoe, the height of the heelis preferably between 10 mm and 20 mm. In so doing, one obtains a heightH₂ between the lower free end of the heel 8 and the ground 7, whichheight is less than the height H₁ of the known style of FIG. 1 by anamount equal to the height of the heel. The distance, and therewith thetime, for the rearward rolling-off process of ball to heel iscorrespondingly considerably reduced with the athletic shoe of thepresent invention in comparison to the known athletic shoe. For optimumutilization of the rebound effect it is also advantageous if the step ortread surface of the heel 8 is kept as large as possible, at least 30 mmby 30 mm, preferably, however, more than 40 mm by 40 mm. In order toreduce the weight of the already lightweight material of the heel 8still further, it may be advantageous if the heel 8 is provided with ahollow section 9 which is preferably open toward the foot side. In thiscase, the welt piece 5 can be eliminated in the region of the heel 3. Itis sufficient if the knobby rubber sole or crepe rubber sole 6 coversthe running surface of the heel 8. A covering on the side surfaces ofthe heel is not necessary, and for the purpose of weight, is also notexpedient.

Naturally, it is not necessary that the knobby rubber sole or the creperubber sole 6 extend over the entire running surface of the racing shoe.In the forward sole region 2, a known soleplate or polyamide andclaw-like gripping elements may also be provided. Such a design isparticularly suitable for synthetic race courses.

The present invention is, of course, not restricted to use as racingshoes, but is also suitable for any other athletic shoe for any othertype of contest, especially for football and soccer shoes, handballshoes, tennis shoes, basketball shoes, etc.

With athletic shoes provided with supports or knobs, such as footballand soccer shoes, it is expedient if the heel 8 comprise hard rubber, orsome other material which is secure against being punctured, in order toavoid pressure points caused by the supports or knobs. With this type ofdesign, heel heights of 8 mm to 10 mm are sufficient and advantageous.Also, such an increase of the heel already supports the forward positionof the player or athlete, which forward position is desired for quickaccelerations or for slowing down very fast.

It is important that the heel 8 provided in the heel region 3 not impairthe flexibility of the outer sole 6, as is the case with knownwedge-shaped sole reinforcers, which extend from the heel up to the ballsection of the shoe, and are particularly known with jumping shoes. Sucha heel or wedge, which is extended toward the front, would not beexpedient when using the present invention for races, especiallysprints.

Due to the small distance H₂ between the lower heel surface and theground 7 during the rearward rolling-off process of balls 2 to heel 3,and the relatively large heel surface, one obtains a pronounced reboundeffect, which generates a force component P₂ which extends at an angleto the contact surface 7 with a resulting accelerating force componentP_(L) in the direction of running.

The heel 8 can, of course, also be integrated with the outer sole. Theopportunity for doing this is particularly presented with sprayed soles,such as polyamide soles for football and soccer shoes. In this casealso, if necessary, the weight-saving hollow section or recess 9 can becast-in during the course of manufacture.

The present invention is, of course, in no way limited to the specificshowing of the drawing, but also encompasses any modifications withinthe scope of the appended claims.

What I claim is:
 1. A lightweight athletic racing shoe, which comprisesin combination:a very flexible outer sole, of wear-resistant material,having a forward sole region with gripping elements as well as a heelsection with a clearly elevated position occupied with respect to theforward sole region; and a heel associated with said heel section ofsaid outer sole, the height of said heel being sufficient to impart tothe wearer of said athletic racing shoe, when the wearer during forwardmovement places said heel on the ground, an acceleration componentdirected in the direction of said movement.
 2. An athletic racing shoeaccording to claim 1, in which a welt is provided in the heel section ofsaid outer sole, and in which said heel is a separate piece insertedbetween said welt and said outer sole.
 3. An athletic racing shoe incombination according to claim 1, in which said heel is made offlexible, elastic material which is only relatively slightly volumecompressible.
 4. An athletic racing shoe in combination according toclaim 3, in which said elastic material is solid rubber.
 5. An athleticracing shoe in combination according to claim 1, in which said outersole is provided with knobs and said heel comprises hard rubber.
 6. Anathletic racing shoe in combination according to claim 1, in which saidheel has a height of more than 8 mm.
 7. An athletic racing shoe incombination according to claim 6, in which said heel has a height of10-20 mm.
 8. An athletic racing shoe in combination according to claim1, in which said heel has a surface for contact with the ground of atleast 30 mm by 30 mm.
 9. An athletic racing shoe in combinationaccording to claim 8, in which said heel has a contact surface with theground of more than 40 mm by 40 mm.
 10. An athletic racing shoe incombination according to claim 1, in which said heel is provided with ahollow section.
 11. An athletic racing shoe in combination according toclaim 10, in which said hollow section is open toward the foot side ofsaid shoe.
 12. An athletic racing shoe in combination according to claim1, in which at least that surface of said heel which is intended forcontact with the ground is covered with wear-resistant material.
 13. Anathletic racing shoe in combination to claim 12, in which saidwear-resistant material is selected from the group consisting of knobbyrubber sole material and crepe rubber sole material.